I used to have a Whisperlite - very reliable, easy to use, and if you're just boiling water, it's great. Don't try rice or anything requiring lower temperatures though.

My new stove (a fabulous Christmas present accompanying an Outback Oven) is an Optimus Nova+. It got some bad PR a couple years back due to an O-ring problem and subsequent recall, but it's a solid stove with great simmering capabilities (like the Dragonfly).

I'm a big fan of multi-fuel/white gas stoves, as the bottles are reusable. You can also open up the bottle and see how much fuel you have left, and you can buy white gas pretty much anywhere (or in a pinch, use pretty well any kind of petrochemical). Canister stoves are easier to use, as you don't need to prime them, but that's about the only advantage I can see.

My roommate has an alcohol stove, and we take that on short backpacking trips. It's nice because it's silent and the fuel doesn't stink, and with a bit of coercion you can get it to simmer. However, it chews through a ton of fuel (probably double the amount a white gas stove uses), so the weight savings balance out in the end. In addition, alcohol stoves are very slow... don't expect coffee right away in the morning!

All in all, all types of stoves have their advantages and disadvantages. These are just my opinions, but for my usage (mainly backpacking where I'm away from cities), the white gas/multifuel stoves win.

Edit: I just saw that you're a group of five. I would steer clear of alcohol in this case - you'll be chewing through a lot of fuel, very slowly. I'm not sure how long it would take to boil a litre of water (15 minutes perhaps?), but most alcohol stoves recommend only boiling half a litre at a time.